Dishwasher appliance with a drying system

ABSTRACT

A dishwasher appliance that includes a drying system is provided. In one exemplary aspect, the drying system includes an inlet duct having an inlet fan and a heating element disposed therein. The inlet fan is operable to draw ambient air into the inlet duct and move the air through the inlet duct into a tub of the dishwasher. The heating element heats the air passing through the inlet duct. The heated air facilitates drying of the articles within the wash chamber of the tub. The heated and pressurized air within the tub is forced into a vent duct positioned within a door of the dishwasher. An ambient fan draws ambient air into the vent duct to mix with the relatively hot and damp air forced out of the wash chamber by the inlet fan, e.g., to lower the dew point of the air exiting the dishwasher.

FIELD OF THE INVENTION

The present subject matter relates generally to dishwasher appliances and more particularly to drying systems for dishwasher appliances.

BACKGROUND OF THE INVENTION

Modern dishwashers typically include a wash chamber where detergent, water, and heat can be applied to clean food or other materials from dishes and other articles being washed. Various cycles may be part of the overall cleaning process. For example, a typical user-selected cleaning option may include a wash cycle and rinse cycle (referred to collectively as a wet cycle), as well as a drying cycle.

Some dishwashers include exposed heating elements within the wash chamber of the tub to facilitate drying of the dishes during the drying cycle. For instance, the exposed heating elements may heat the air within the wash chamber, which increases the moisture carrying capacity of the air and the amount of evaporation within the wash chamber of the tub. However, such “exposed” heating elements take up valuable space within the tub and may be costly, e.g., to install and maintain. Some dishwashers are “hidden heat” models that do not include heating elements within the wash chamber of the tub. Thus, heat may be imparted to the wash chamber in a different manner to facilitate drying of the dishes during a drying cycle. For instance, one solution has been to increase the temperature of the water during the final wash or rinse cycle with the aim of storing the thermal energy in the wash chamber during the drying cycle. Another solution has been to use desiccant material to absorb the moisture from the air and redistribute the hot air back into the tub (e.g., in a closed loop system). However, such solutions may require considerable energy to execute, have longer cycle times, and/or have unsatisfactory drying performance.

Accordingly, a dishwasher appliance that addresses one or more of the challenges noted above would be useful.

BRIEF DESCRIPTION OF THE INVENTION

Aspects and advantages of the invention will be set forth in part in the following description, or may be apparent from the description, or may be learned through practice of the invention.

In one example embodiment, a dishwasher appliance is provided. The dishwasher appliance includes a tub defining a wash chamber. Further, the dishwasher appliance includes a door mounted to the tub dishwasher appliance also includes an inlet duct extending between an inlet in fluid communication with ambient air about the tub and an outlet in fluid communication with the wash chamber of the tub, the inlet duct having an inlet fan and a heating element positioned therein, the inlet fan operable to move ambient air through the inlet duct and the heating element operable to heat ambient air moving through the inlet duct.

In another example embodiment, a dishwasher appliance is provided. The dishwasher appliance includes a tub defining a wash chamber. The dishwasher appliance also includes a door mounted to the tub. Further, the dishwasher appliance includes an inlet duct extending between an inlet in fluid communication with ambient air about the tub and an outlet in fluid communication with the wash chamber of the tub. Moreover, the dishwasher appliance includes an inlet fan positioned within or at the inlet duct, the inlet fan operable to move ambient air through the inlet duct. The dishwasher appliance further includes a heating element positioned within or at the inlet duct, the heating element operable to heat ambient air moving through the inlet duct. In addition, the dishwasher appliance includes a vent duct having a tub channel and an ambient channel positioned within the vent duct such that the tub channel is separate from the ambient channel, an inlet of the tub channel positioned in fluid communication with the wash chamber, an inlet of the ambient channel positioned in fluid communication with ambient air about the tub. The dishwasher appliance also includes an insert positioned within the vent duct, the insert and the vent duct collectively defining an outlet of the tub channel and an outlet of the ambient channel, the insert positioned between the outlet of the tub channel and the outlet of the ambient channel. The dishwasher appliance further includes an ambient fan mounted within or at the ambient channel of the vent duct, the ambient fan operable to flow ambient air about the tub through the ambient channel from the inlet of the ambient channel to the outlet of the ambient channel.

These and other features, aspects and advantages of the present invention will become better understood with reference to the following description and appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

A full and enabling disclosure of the present invention, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended figures, in which:

FIG. 1 provides a front elevation view of a dishwasher appliance in accordance with one embodiment of the present disclosure;

FIG. 2 provides a perspective view of the dishwasher appliance of FIG. 1 with various exterior components removed;

FIG. 3 provides a perspective view of an inlet duct of the dishwasher appliance of FIGS. 1 and 2;

FIG. 4 provides a section view of a vent duct of the dishwasher appliance of FIGS. 1 and 2;

FIG. 5 provides a schematic view of the vent duct of FIG. 4 and mixing between ambient air and wash chamber air within the vent duct;

FIG. 6 provides a section view of a bottom end of an exemplary vent duct having a diverter in accordance with exemplary embodiments of the present disclosure; and

FIG. 7 provides an exemplary method for operating a dishwasher appliance in a drying cycle in accordance with an exemplary embodiment of the present disclosure.

DETAILED DESCRIPTION

Reference now will be made in detail to embodiments of the invention, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For instance, features illustrated or described as part of one embodiment can be used with another embodiment to yield a still further embodiment. Thus, it is intended that the present invention covers such modifications and variations as come within the scope of the appended claims and their equivalents. As used herein, terms of approximation, such as “approximately,” “substantially,” or “about,” refer to being within a twenty-five percent (25%) margin of error.

FIGS. 1 and 2 depict an example dishwasher appliance 100 that may be configured in accordance with aspects of the present disclosure. It should be appreciated that the invention is not limited to any particular style, model, or other configuration of dishwasher, and that the embodiment depicted in FIGS. 1 and 2 is for illustrative purposes only. Further, dishwasher appliance 100 defines a vertical direction V, a lateral direction L, and a transverse direction T (FIG. 2). The vertical direction V, lateral direction L, and transverse direction T are mutually perpendicular and form an orthogonal direction system.

As shown, dishwasher appliance 100 includes a tub 102 that defines a wash chamber 104 within an interior of tub 102. Wash chamber 104 is configured for the receipt of articles for cleaning, such as dishes, cups, utensils, etc. Tub 102 includes a front opening (not shown) and a door 106 with a handle 107. Door 106 extends between a top portion 108 and a bottom portion 109 along the vertical direction V, and door 106 is hinged at or near bottom portion 109 of door 106 for movement between a normally closed vertical position (shown in FIGS. 1 and 2), wherein wash chamber 104 is sealed shut for washing operation, and a horizontal open position for loading and unloading of articles from wash chamber 104.

Dishwasher appliance 100 includes various components for applying wash fluid onto articles within wash chamber 104 and for supporting the articles within wash chamber 104. Such components are well known in the art and are not shown or described in detail herein. As an example, dishwasher appliance 100 may include racks for supporting articles for washing within wash chamber 104, spray assemblies for directing flows of wash fluid onto the articles within the racks, silverware baskets, etc. The racks may be adapted for movement between an extended loading position in which the racks are substantially positioned outside the wash chamber 104 and a retracted position in which the racks are located inside the wash chamber 104. The spray assemblies may include rotatable spray arms mounted to tub 102 and/or one of the racks.

As shown in FIG. 1, dishwasher appliance 100 is equipped with a controller 120 to regulate operation of dishwasher 100, e.g., in a drying cycle. Controller 120 may include one or more memory devices and one or more processors, such as general or special purpose microprocessors operable to execute programming instructions or micro-control code associated with a cycle of dishwasher appliance 100. The memory may represent random access memory such as DRAM, or read only memory such as ROM or FLASH. In some embodiments, the processor executes programming instructions stored in memory. The memory may be a separate component from the processor or may be included onboard within the processor. Alternatively, controller 120 may be constructed without using a microprocessor, e.g., using a combination of discrete analog and/or digital logic circuitry (such as switches, amplifiers, integrators, comparators, flip-flops, AND gates, and the like) to perform control functionality instead of relying upon software.

Controller 120 may be positioned in a variety of locations throughout dishwasher 100. In the illustrated embodiment of FIG. 1, controller 120 is located within a control panel area of door 106. In such an embodiment, input/output (“I/O”) signals may be routed between the controller 120 and various operational components of dishwasher appliance 100 along wire harnesses that may be routed through the bottom of door 116. Dishwasher appliance 100 may include a user interface panel/controls through which a user may select various operational features and modes and monitor progress of dishwasher appliance 100. In one embodiment, the user interface may represent a general purpose I/O (“GPIO”) device or functional block. In one embodiment, the user interface may include input components, such as one or more of a variety of electrical, mechanical or electro-mechanical input devices including rotary dials, push buttons, and touch pads. The user interface may include a display component, such as a digital or analog display device designed to provide operational feedback to a user. The user interface may be communicatively coupled with controller 120 via one or more signal lines or shared communication busses.

Dishwasher appliance 100 includes a temperature sensing device or temperature sensor 122 (FIG. 3). Temperature sensor 122 is configured to sense the temperature of the air entering wash chamber 104 or air indicative of the air within wash chamber 104, such as by sensing the air within an inlet duct 210 (FIG. 2), e.g., during or upon commencement of a drying cycle. Temperature sensor 122 is communicatively coupled with controller 120 (FIG. 1), e.g., so that controller 120 may make decisions based at least in part on one or more outputs (e.g., temperature signals) generated by temperature sensor 122. For instance, controller 120 may receive one or more temperature signals indicative of the temperature of the air within wash chamber 104 or within inlet duct 210, and based at least in part on the temperature signals, controller 120 can activate various components during a drying cycle as will be explained in greater detail herein.

In general, dishwasher appliance 100 may utilize a variety of cycles to wash and, optionally, dry articles within wash chamber 104. For example, a wet cycle is utilized to wash articles. The wet cycle may include a main wash cycle and a rinse cycle, as well as an optional pre-wash cycle. During each such cycle, water or another suitable liquid may be utilized in wash chamber 104 to interact with and clean articles therein. The liquid may additionally mix with, for example, detergent or other various additives that are released into the wash chamber 104 during various sub-cycles of the wet cycle. A drying cycle may be utilized to dry articles after washing. In general, no liquid is sprayed or otherwise produced during the drying cycle.

During the drying cycle, liquid water on the articles within wash chamber 104 evaporates. The water vapor is flowable out of wash chamber 104 in order to improve drying performance of dishwasher appliance 100. Dishwasher appliance 100 includes various features for flowing hot air into wash chamber 104 to increase the temperature of the air therein and flowing air and water vapor from wash chamber 104, e.g., during drying cycles. In addition, dishwasher appliance 100 includes features for limiting or preventing condensation formation on a floor adjacent to dishwasher appliance 100 when air and water vapor flows from wash chamber 104.

As shown in FIG. 2, dishwasher appliance 100 includes a drying system 200, e.g., for executing a drying cycle of dishwasher appliance 100. Drying system 200 includes, among other components, an inlet duct 210 and a vent duct 250. For this embodiment, generally, inlet duct 210 is mounted to a side of tub 102 and vent duct 250 is positioned within door 106. In alternative example embodiments, vent duct 250 may be mounted to other suitable locations, e.g., to a side of tub 102. In addition, in some alternative embodiments, inlet duct 210 may be mounted to tub 102 at other suitable locations.

Inlet duct 210 extends between an inlet 212 in fluid communication with ambient air about tub 102 and an outlet 214 in fluid communication with wash chamber 104 of tub 102. An inlet fan 216 is mounted to inlet duct 210 and is positioned therein. Inlet fan 216 positioned within inlet duct 210 is operable to flow air from wash chamber 104 into vent duct 250. In particular, inlet fan 216 may draw ambient air from below tub 102 into wash chamber 104 thereby pressuring wash chamber 104 relative to the ambient air about dishwasher appliance 100. The pressurized air and water vapor within wash chamber 104 exits wash chamber 104 via vent duct 250.

Vent duct 250 extends between various inlets and a vent outlet 260. Particularly, vent duct 250 includes a tub inlet 256 in fluid communication with wash chamber 104, e.g., when door 106 is closed. Thus, air and water vapor from wash chamber 104 may flow into vent duct 250 at tub inlet 256. Vent duct 250 also includes an ambient inlet 258. Ambient inlet 258 is positioned in fluid communication with ambient air about tub 102. An ambient fan 262 is mounted to vent duct 250 and is operable to flow ambient air from about dishwasher appliance 100 into vent duct 250. Thus, the ambient air about tub 102 may flow into vent duct 250 at ambient inlet 258, e.g., during operation of ambient fan 262. Within vent duct 250, the ambient air drawn into vent duct 250 by ambient fan 262 mixes with the wash chamber air forced through tub inlet 256 by inlet fan 216 as discussed in detail below.

A speed of inlet fan 216 and a speed of ambient fan 262 are variable. Thus, e.g., a flow rate of air from wash chamber 104 into vent duct 250 may be advantageously adjusted by changing the speed of inlet fan 216. Similarly, a flow rate of ambient air from about dishwasher appliance 100 into vent duct 250 may be advantageously adjusted by changing the speed of ambient fan 262. The speed of ambient fan 262 and the speed of inlet fan 216 may be separately adjusted to advantageously adjust the ratio of ambient air from about dishwasher appliance 100 flowing into vent duct 250 to air from wash chamber 104 flowing into vent duct 250. The fans 216, 262 may be adjusted, e.g., in accordance with control commands from controller 120 (FIG. 1).

FIG. 3 provides a perspective view of inlet duct 210 of dishwasher appliance 100 of FIGS. 1 and 2. As noted above, inlet duct 210 extends between inlet 212 in fluid communication with ambient air A about tub 102 (FIG. 2) and outlet 214 in fluid communication with wash chamber 104 (FIG. 2) of tub 102. Further, inlet duct 210 has inlet fan 216 that is operable to move ambient air A through inlet duct 210. Notably, a heating element 218 is positioned within inlet duct 210. Heating element 218 may be any suitable type of heating element, such as e.g., an electric resistance heating element. Heating element 218 is operable to heat ambient air A moving through the inlet duct 210, e.g., during a drying cycle. That is, as inlet fan 216 moves or draws ambient air A into inlet duct 210 at inlet 212 and moves the ambient air A through heating element 218, heating element 218 heats the ambient air A. As shown in FIG. 3, the resultant heated air HA flows downstream to outlet 214 where the heated air HA flows into wash chamber 104 of tub 102. The heated air HA pressurizes and raises the temperature of the air within wash chamber 104. The higher temperature of the air within wash chamber 104 increases its moisture carrying capacity and the amount of evaporation within wash chamber 104. The pressured air within wash chamber 104 also forces some of the air through tub inlet 256 of vent duct 250 (FIG. 2). As discussed in greater detail below, with reference to FIG. 2, vent duct 250 includes features that facilitate mixing of the ambient air moved into vent duct 250 by ambient fan 262 and the heated air HA moved through wash chamber 104 by inlet fan 216 to advantageously reduce or eliminate condensation of water vapor onto a floor adjacent dishwasher appliance 100 or other surface around dishwasher appliance 100.

As further shown in FIG. 3, heating element 218 is positioned downstream of inlet fan 216 within inlet duct 210. Such positioning ensures that inlet fan 216 moves relatively cool ambient air as opposed to the relatively hot heated air HA. In this way, inlet fan 216 may be formed of less expensive materials. However, in alternative embodiments, heating element 218 may be positioned upstream of inlet fan 216 within inlet duct 210.

In some embodiments, controller 120 (FIG. 1) is communicatively coupled with temperature sensor 122 (FIG. 3) and heating element 218, e.g., by a suitable wired or wireless connection. In such embodiments, controller 120 is configured to receive, from temperature sensor 122, one or more temperature signals indicative of a temperature of the air entering wash chamber 104 of tub 102. Such signals may be received prior to commencement of a drying cycle and/or during the drying cycle. Moreover, controller 120 is configured to activate or deactivate heating element 218 based at least in part on the one or more temperature signals. For instance, the sensed temperature of the air entering wash chamber 104 may be compared to a temperature threshold. Controller 120 may activate or deactivate heating element 218 depending on whether the temperature of the air is above or below the temperature threshold. For instance, if the temperature is above the threshold, controller 120 may not activate, may deactivate, or may pulse heating element 218 at predetermined intervals at a predetermined power level. If, however, the temperature is below the threshold, controller 120 may activate and pulse heating element 218 continuously or at predetermined intervals, e.g., that are more frequent than the predetermined intervals set by controller 120 if the sensed temperature was determined to be above the threshold. Further, the power levels at which heating element 218 may be powered may be more powerful than the power levels set by controller 120 if the sensed temperature was determined to be above the threshold.

Moreover, in some embodiments, heating element 218 is a first heating element and dishwasher appliance 100 includes a second heating element 220 positioned within inlet duct 210. For the depicted embodiment of FIG. 3, second heating element 220 is positioned within first heating element 218. However, in alternative embodiments, second heating element 220 may be positioned upstream or downstream of first heating element 218. Second heating element 220 may be any suitable type of heating element and is operable to heat ambient air A (or heated air HA already heated by first heating element 218) moving through inlet duct 210, e.g., during a drying cycle. In some embodiments, controller 120 (FIG. 1) is communicatively coupled with temperature sensor 122 (FIG. 3), first heating element 218, and second heating element 220, e.g., by a suitable wired or wireless connection. In such embodiments, controller 120 is configured to receive, from temperature sensor 122, one or more temperature signals indicative of a temperature of the air entering wash chamber 104 of tub 102. Such signals may be received prior to commencement of a drying cycle and/or during the drying cycle. Moreover, controller 120 is configured to activate or deactivate one or both of first heating element 218 and second heating element 220 based at least in part on the one or more temperature signals. For instance, the temperature of the air entering wash chamber 104 may be compared to a temperature threshold. If the sensed temperature exceeds the temperature threshold, controller 120 may activate only first heating element 218 and/or deactivate second heating element 220. In contrast, if the sensed temperature is below the temperature threshold, controller 120 may activate both first and second heating elements 218, 220, e.g., to raise the temperature of the air within wash chamber 104 to increase the moisture holding capacity of the air. In addition, in some embodiments, dishwasher appliance 100 may include more than two (2) heating elements. In such embodiments, controller 120 may control the heating elements to control the temperature of the air entering wash chamber 104, e.g., in a similar manner as noted above.

For this embodiment, inlet duct 210 has a horizontal component 224 that defines inlet 212 of inlet duct 210. As shown in FIGS. 2 and 3, horizontal component 224 extends at least partially beneath tub 102 along the vertical direction V such that inlet 212 of inlet duct 210 is positioned beneath tub 102 along the vertical direction V. Accordingly, inlet 212 is positioned in a location in which there is adequate ambient air for inlet fan 216 to draw from, e.g., during a drying cycle. Moreover, heating element 218 is positioned beneath tub 102 along the vertical direction V. Thus, such components are protected under tub 102, e.g., during transport. Moreover, heating element 218 is placed in a location that is out of a user's reach, e.g., during operation of a drying cycle.

As further depicted in FIG. 3, inlet duct 210 also has a vertical component 226 that defines outlet 214 of inlet duct 210. Vertical component 226 is connected to and in fluid communication with horizontal component 224 and is connected to a side of tub 102 (FIG. 2). In particular, a transition portion 222 of horizontal component 224 is connected with a bottom portion of vertical component 226. Transition portion 222 transitions air flowing through inlet duct 210 from substantially along a horizontal direction (i.e., a direction orthogonal to the vertical direction V) to substantially along a vertical direction, e.g., along the vertical direction V. Vertical component 226 may be connected to tub 102 and horizontal component 224 in any suitable fashion, e.g., by mechanical fasteners. In some embodiments, horizontal component 224 and vertical component 226 may be integrally formed as a unitary, monolithic component, e.g., and formed with an additive manufacturing process.

In some example embodiments, inlet duct 210 has a water inlet 228 positioned upstream of heating element 218. Water inlet 228 may be in fluid communication with an external water source, e.g., via one or more water supply conduits, and water may flow through into inlet duct 210, e.g., during a wet cycle. As shown in FIG. 3, water inlet 228 is positioned above outlet 214 of inlet duct 210 along the vertical direction V. Further, inlet duct 210 defines a water funnel 230. More particularly, a top portion of vertical component 226 defines water funnel 230. As shown, outlet 214 of inlet duct 210 is defined at a bottom end 232 of water funnel 230. Water inlet 228 is positioned such that water W flowing through water inlet 228, e.g., during a wet cycle, flows into water funnel 230 and through outlet 214 of inlet duct 210 and into wash chamber 104 of tub 102 (FIG. 2). Particularly, water funnel 230 is shaped such that water W is prevented from flowing upstream toward inlet 212 of inlet duct 210. In this way, water W is prevented from flowing upstream to heating element 218. Accordingly, during a wet cycle, water W may enter inlet duct 210 at water inlet 228 and flow downstream to wash chamber 104 of tub 102 (FIG. 2) through outlet 214 of inlet duct 210. During a drying cycle, water W may cease flowing into inlet duct 210 at water inlet 228 and ambient air A may be drawn into inlet duct 210 and forced passed heating element 218 and eventually into tub 102 to raise the pressure and temperature of the air within wash chamber 104, e.g., in a manner described above. The dual use of inlet duct 210 saves space and reduces the cost and number of parts of dishwasher appliance 100.

FIG. 4 provides a section view of vent duct 250 and depicts an insert 264 of dishwasher appliance 100 positioned within vent duct 250. As discussed in greater detail below, vent duct 250 and insert 264 cooperate to facilitate mixing of ambient air drawn into vent duct 50 by ambient fan 262 and the wash chamber air from inlet fan 216 to advantageously reduce or eliminate condensation of water vapor onto a floor adjacent dishwasher appliance 100 or other surface around dishwasher appliance 100.

As shown in FIG. 4, a tub channel 252 and an ambient channel 254 are positioned within vent duct 250. In particular, vent duct 250 may define at least a portion of tub channel 252 and at least a portion of ambient channel 254. Tub channel 252 is separate from ambient channel 254 within vent duct 250. For example, walls of vent duct 250 and/or insert 264 may be positioned between tub channel 252 and ambient channel 254 within vent duct 250. Thus, e.g., air within tub channel 252 may not mix with air from ambient channel 254 except at outlets of tub channel 252 and ambient channel 254, as discussed in detail below.

An inlet 256 of tub channel 252 is positioned in fluid communication with wash chamber 104, e.g., when door 106 is closed. Thus, air and water vapor from wash chamber 104 (FIG. 2) may flow into tub channel 252 at inlet 256 of tub channel 252, e.g., during operation of inlet fan 216 (FIG. 2) in a drying cycle. An inlet 258 (FIG. 2) of ambient channel 254 is positioned in fluid communication with ambient air about tub 102. Thus, the ambient air about tub 102 may flow into ambient channel 254 at inlet 258 of ambient channel 254, e.g., during operation of ambient fan 262 in a drying cycle.

Insert 264 is positioned within vent duct 250. Insert 264 and vent duct 250 collectively define at least a portion of tub channel 252 and at least a portion of ambient channel 254. In particular, insert 264 and vent duct 250 collectively define an outlet 266 of tub channel 252 and an outlet 268 of ambient channel 254. After entering tub channel 252 at inlet 256 of tub channel 252, the air and water vapor from wash chamber 104 may flow through tub channel 252 to outlet 266 of tub channel 252, e.g., during operation of inlet fan 216. Similarly, after entering ambient channel 254 at inlet 258 of ambient channel 254, the ambient air about tub 102 (FIG. 2) may flow through ambient channel 254 to outlet 268 of ambient channel 254, e.g., during operation of ambient fan 262. In such a manner, separate flows of relatively cool, dry ambient air and relatively hot, damp wash chamber air may flow through vent duct 250.

Insert 264 may be positioned between outlet 266 of tub channel 252 and outlet 268 of ambient channel 254 along the transverse direction T. Thus, insert 264 may block mixing of the separate flows of relatively cool, dry ambient air and relatively hot, damp wash chamber air within vent duct 250 upstream of outlets 266, 268. In other words, insert 264 may be positioned within vent duct 250 such that the flows of relatively cool, dry ambient air and relatively hot, damp wash chamber air mix downstream of insert 264 and outlets 266, 268. Outlets 266, 268 may be sized to facilitate mixing of the flows of relatively cool, dry ambient air and relatively hot, damp wash chamber air.

Outlet 266 of tub channel 252 has a width WT along the lateral direction L. Similarly, outlet 268 of ambient channel 254 has a width WA along the lateral direction L. The width WT of outlet 266 of tub channel 252 may be about equal to the width WA of outlet 268 of ambient channel 254. As used herein, the term “about” means within ten percent of the stated width when used in the context of widths. The width WT of outlet 266 of tub channel 252 and the width WA of outlet 268 of ambient channel 254 may be suitably sized. For example, the width WT of outlet 266 of tub channel 252 may be no less than four inches (4″). Similarly, the width WA of outlet 268 of ambient channel 254 may be no less than four inches (4″). As another example, the width WA of outlet 268 of ambient channel 254 may be no less than half the width WT of outlet 266 of tub channel 252 and no greater than the width WT of outlet 266 of tub channel 252. Such sizing of outlets 266, 268 advantageously encourages uniform mixing of the separate flows of relatively cool, dry ambient air and relatively hot, damp wash chamber air from tub channel 252 and ambient channel 254 downstream of outlets 266, 268, e.g., as shown in FIG. 5.

Outlet 266 of tub channel 252 may also be aligned with outlet 268 of ambient channel 254 along the transverse direction T (a direction into and out of the page in FIG. 4). Thus, e.g., outlet 266 of tub channel 252 may be positioned coplanar with outlet 268 of ambient channel 254, e.g., in a plane that is perpendicular to the vertical direction V. Such positioning of outlets 266, 268 advantageously encourages uniform mixing of the separate flows of relatively cool, dry ambient air and relatively hot, damp wash chamber air from tub channel 252 and ambient channel 254 downstream of outlets 266, 268, e.g., as shown in FIG. 5.

Inlet 258 of ambient channel 254 is positioned proximate bottom portion 109 of door 106, e.g., as shown in FIG. 2. Conversely, outlet 268 of ambient channel 254 is spaced from bottom portion 109 of door 106. For example, outlet 268 of ambient channel 254 may be positioned at a middle portion of door 106 between top and bottom 108, 109 of door 106 (FIG. 2) along the vertical direction V. Thus, e.g., outlet 268 of ambient channel 254 may be positioned above inlet 258 of ambient channel 254 along the vertical direction V when door 106 is closed. Inlet 256 of tub channel 252 may be positioned at top portion 108 of door 106, e.g., as shown in FIG. 2. Conversely, outlet 266 of tub channel 252 is spaced from top portion 108 of door 106. For example, outlet 266 of tub channel 252 may be positioned at the middle portion of door 106 between top and bottom 108, 109 of door 106 (FIG. 2) along the vertical direction V. Thus, e.g., outlet 266 of tub channel 252 may be positioned below inlet 256 of tub channel 252 along the vertical direction V when door 106 is closed.

A mixed air channel 270 is also positioned within vent duct 250. For example, mixed air channel 270 may be defined by vent duct 250. Mixed air channel 270 extends from outlets 266, 268 to an outlet 260 (FIG. 2) of mixed air channel 270. Outlet 260 of mixed air channel 270 is positioned at bottom portion 109 of door 206 (FIG. 2). Thus, mixed air channel 270 may extend downward along the vertical direction V from outlets 266, 268 to outlet 260 of mixed air channel 270. The separate flows of relatively cool, dry ambient air and relatively hot, damp wash chamber air from tub channel 252 and ambient channel 254 may mix within mixed air channel 270 after exiting outlets 266, 268 and prior to exiting vent duct 250 at outlet 260 of mixed air channel 270.

Mixed air channel 270 has a length, e.g., extending between outlets 266, 268 and outlet 260 along the vertical direction V. The length of mixed air channel 270 may be a suitable length. For example, the length of mixed air channel 270 along the vertical direction V may be selected to facilitate mixing of the separate flows of relatively cool, dry ambient air and relatively hot, damp wash chamber air from tub channel 252 and ambient channel 254. In particular, the length of mixed air channel 270 may be no less than twelve inches (12″). Such sizing of the length of mixed air channel 270 may advantageously allow sufficient time for the separate flows of relatively cool, dry ambient air and relatively hot, damp wash chamber air from tub channel 252 and ambient channel 254 to mix within mixed air channel 270 downstream of outlets 266, 268 and prior to such flow exiting mixed air channel 270 at outlet 260 of mixed air channel 270.

Vent duct 250 and/or insert 264 may include features for diffusing the separate flows of relatively cool, dry ambient air and relatively hot, damp wash chamber air along the lateral direction L prior to mixing of such separate flows. In particular, as shown best in FIG. 4, a cross-section of tub channel 252 in a plane that is perpendicular to the vertical direction V (when door 106 (FIG. 2) is closed) expands along the vertical direction V towards outlet 266 of tub channel 252. Similarly, a cross-section of ambient channel 254 in a plane that is perpendicular to the vertical direction V (when door 106 (FIG. 2) is closed) expands along the vertical direction V towards outlet 268 of ambient channel 254. By expanding towards outlets 266, 268, the velocities of fluid flow within tub channel 252 and ambient channel 254 may likewise decrease prior to contact between the separate flows of relatively cool, dry ambient air and relatively hot, damp wash chamber air at outlets 266, 268 thereby encouraging mixing between the separate flows.

As shown in FIG. 4, in some embodiments, dishwasher appliance 100 may also include a first plurality of guide vanes 272 and a second plurality of guide vanes 274. First guide vanes 272 are positioned within tub channel 252. First guide vanes 272 are spaced apart along the lateral direction L, e.g., such that air within tub channel 252 flows between first guide vanes 272 along the vertical direction V. Each of first guide vanes 272 also extends between vent duct 250 and insert 264 along the transverse direction T adjacent outlet 266 of tub channel 252. First guide vanes 272 may be positioned and oriented to distribute air flowing through tub channel 252 across the width WT of outlet 266 of tub channel 252.

Second guide vanes 274 are positioned within ambient channel 254, e.g., opposite first guide vanes 272 about insert 264 along the transverse direction T. Second guide vanes 274 are spaced apart along the lateral direction L, e.g., such that air within ambient channel 254 flows between second guide vanes 274 along the vertical direction V. Each of second guide vanes 274 also extends between vent duct 250 and insert 264 along the transverse direction T adjacent outlet 268 of ambient channel 254. Second guide vanes 274 may be positioned and oriented to distribute air flowing through ambient channel 254 across the width WA of outlet 268 of ambient channel 254.

First guide vanes 272 and second guide vanes 274 may be integrally formed on or with vent duct 250 or insert 264. Thus, first guide vanes 272 may be formed on one of vent duct 250 or insert 264. Similarly, second guide vanes 274 may be formed on one of vent duct 250 or insert 264. Vent duct 250 and insert 264 may each be formed from separate pieces of molded plastic in certain example embodiments. In alternative example embodiments, vent duct 250 and insert 264 may be unitary, e.g., and formed with an additive manufacturing process.

The various components of dishwasher appliance 100 cooperate to uniformly mix ambient air with wash chamber air within vent duct 250, e.g., during drying cycles. As shown in FIG. 5, the ambient air (shown with dot-dashed arrows and labeled with an “A”) from ambient channel 254 mixes uniformly with the wash chamber air (shown with dashed arrows and labeled with an “CA”) from tub channel 252 to lower the dew point of the air prior to exiting vent duct 250. The mixture of ambient air A and the wash chamber air CA is shown with the solid arrows and labeled as “MA”. Thus, no unmixed separate stream of wash chamber air may exit outlet 260 of mixed air channel 270 and thereby form water condensation on a floor adjacent outlet 260 of mixed air channel 270.

In some embodiments, as shown in FIG. 6, dishwasher appliance 100 (FIGS. 1 and 2) includes a diverter 280 positioned at outlet 260 of mixed air channel 270 of vent duct 250. Diverter 280 is operable to transition mixed air MA flowing through mixed air channel 270 from substantially along the vertical direction V to substantially along a horizontal direction (i.e., a direction orthogonal to the vertical direction V). That is, diverter 280 transitions mixed air MA about ninety degrees) (90°. In this way, when the mixed air MA exits outlet 260, the mixed air MA is directed outward from dishwasher appliance 100 in a plane orthogonal to the vertical direction V, and consequently, the mixed air MA is directed outward from dishwasher appliance 100 in a direction that is substantially parallel to the floor. Thus, the mixed air MA is dispersed over a greater area of the floor, e.g., as opposed to being directed straight downward along the vertical direction V onto the floor. This may, for example, prevent pooling of water on a user's floor. Further, in some embodiments, diverter 280 includes one or more diverter vanes 282 (only one shown in FIG. 6) spaced from one another along the lateral direction L (a direction into and out of the page in FIG. 6). In this way, the mixed air MA exiting outlet 260 through diverter 280 may be separated and “fanned out” from dishwasher appliance 100.

In some alternative embodiments, with reference to FIGS. 2 and 4, vent duct 250 need not include ambient fan 262. More broadly, in some embodiments, drying system 200 need not include ambient fan 262 to draw in ambient air at inlet 258 to mix with wash chamber air. In some embodiments, dishwasher appliance 100 may include other features for lowering the dew point of the air exiting dishwasher appliance 100. For instance, vent duct 250 may have a longer exit path, dishwasher appliance 100 may include a condensing device, or the air may be pushed outside instead of outward into a user's home interior.

FIG. 7 provides an exemplary method (300) for operating a dishwasher appliance in a drying cycle in accordance with an exemplary embodiment of the present disclosure. For instance, the method (300) may be utilized to operate dishwasher appliance 100 of FIGS. 1 and 2 in a drying cycle. Accordingly, numerals used to describe the exemplary dishwasher appliance 100 will be utilized below to provide context to method (300).

At (302), the method (300) includes commencing the drying cycle. For instance, the drying cycle may be commenced upon the completion of the wet cycle (e.g., a wash and rinse cycle). Upon commencement of the drying cycle, a water valve of dishwasher appliance 100 may be moved to a closed position such that water does not flow through water inlet 228 of inlet duct 210 (e.g., as shown in FIG. 3).

At (304), the method (300) includes activating an inlet fan, an ambient fan, and a heating element. That is, upon commencement of the drying cycle at (302), controller 120 activates inlet fan 216, ambient fan 262, and heating element 218. Thus, controller 120 is communicatively coupled with inlet fan 216, ambient fan 262, and heating element 218. When controller 120 activates inlet fan 216, ambient fan 262, and heating element 218, ambient air is drawn into inlet duct 210 by inlet fan 216. The ambient air moves downstream through or across heating element 218. That is, heating element 218 imparts thermal energy to the ambient air (e.g., heating element 218 heats the ambient air). The heated air continues downstream through inlet duct 210 where the heated air eventually exits inlet duct 210 at outlet 214 of inlet duct 210. Thus, the heated air enters wash chamber 104 of tub 102. The heated air pressurizes and increases the temperature of the air within wash chamber 104. Accordingly, the moisture holding capacity of the air within wash chamber 104 is increased.

The increased pressure of the air within wash chamber 104 causes some of the air within wash chamber 1042 exit wash chamber 104 of tub 102 at tub inlet 256 of vent duct 250. Thus, the wash chamber air is forced into vent duct 250 mounted to door 106. The wash chamber air is not pulled or sucked into vent duct 250 by ambient fan 262. The wash chamber air flows downstream through tub channel 252 of vent duct 250. Meanwhile, ambient air is drawn into ambient inlet 258 of ambient channel 254 of vent duct 250. The ambient air is pooled vertically upward through ambient channel 254 and is directed into insert 264. Eventually, the ambient air mixes with the wash chamber air at outlets 266, 268 of insert 264. The now mixed air flows downstream in a generally downward direction along the vertical direction V in mixed air channel 270 where the mixed air exits vent duct 250 through outlet 260. In some implementations, diverter 280 positioned at outlet 260 may transition the mixed air from flowing substantially along the vertical direction V to flowing substantially along a horizontal direction (i.e., a direction orthogonal to the vertical direction V).

Moreover, in some implementations, inlet fan 216 and ambient fan 262 may be activated at the same time or simultaneously. By activating inlet fan 216 and ambient fan 262 at the same time, the mass flows within the various ducts and chambers of dishwasher appliance 100 may be achieved more quickly and thus drawing performance is enhanced. Further, in some implementations, heating element 218 is activated simultaneously with inlet fan 216 and ambient fan 262. Thus, heated air is immediately introduced into wash chamber 104 upon commencement of the drying cycle. In some implementations, however, heating element 218 is activated after commencement of the drying cycle at (302).

At (306), in some implementations, the method (300) includes activating a second heating element. For instance, controller 120 may receive, from temperature sensor 122, one or more temperature signals indicative of a temperature of the air within wash chamber 104 of tub 102. Such signals may be received prior to commencement of the drying cycle and/or during the drying cycle. If the temperature exceeds a temperature threshold, controller 120 may activate only heating element 218. On the other hand, if the temperature is below the temperature threshold, controller 120 may activate both heating element 218 and second heating element 220, e.g., to raise the temperature of the air within wash chamber 104 to increase the moisture holding capacity of the air. In alternative implementations, dishwasher appliance 100 may include a humidity sensor. In such implementations, controller 120 may activate heating element 218 and/or second heating element 220 based at least in part on whether the humidity level within wash chamber 104 has exceeded a predetermined humidity threshold.

At (308), the method (300) includes terminating the drying cycle, e.g., after a predetermined time.

This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they include structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims. 

What is claimed is:
 1. A dishwasher appliance, comprising: a tub defining a wash chamber; a door mounted to the tub; an inlet duct extending between an inlet in fluid communication with ambient air about the tub and an outlet in fluid communication with the wash chamber of the tub, the inlet duct having an inlet fan and a heating element positioned therein, the inlet fan operable to move ambient air through the inlet duct and the heating element operable to heat ambient air moving through the inlet duct.
 2. The dishwasher appliance of claim 1, wherein the heating element is positioned downstream of the inlet fan within the inlet duct.
 3. The dishwasher appliance of claim 1, further comprising: a temperature sensor; a controller communicatively coupled with the temperature sensor and the heating element, the controller configured to: receive, from the temperature sensor, one or more temperature signals indicative of a temperature of the air entering the wash chamber; and activate or deactivate the heating element based at least in part on the one or more temperature signals.
 4. The dishwasher appliance of claim 3, wherein the heating element is a first heating element, and wherein the dishwasher appliance further comprises: a second heating element positioned within the inlet duct, and wherein the controller is communicatively coupled with the second heating element, and wherein the controller is further configured to activate or deactivate one or both of the first heating element and the second heating element based at least in part on the one or more temperature signals.
 5. The dishwasher appliance of claim 1, wherein the inlet duct has a horizontal component that defines the inlet of the inlet duct, the horizontal component extends at least partially beneath the tub along a vertical direction such that the inlet of the inlet duct is positioned beneath the tub along the vertical direction.
 6. The dishwasher appliance of claim 5, wherein the inlet duct has a vertical component that defines the outlet of the inlet duct, the vertical component is connected to and in fluid communication with the horizontal component and is connected to the side of the tub.
 7. The dishwasher appliance of claim 1, wherein the inlet duct has a water inlet positioned upstream of the heating element.
 8. The dishwasher appliance of claim 7, wherein the water inlet is positioned above the outlet of the inlet duct along a vertical direction.
 9. The dishwasher appliance of claim 7, wherein the inlet duct defines a water funnel, and wherein the outlet of the inlet duct is defined at a bottom end of the water funnel, and wherein the water inlet is positioned such that water flowing through the water inlet flows into the water funnel and through the outlet of the inlet duct and into the wash chamber of the tub.
 10. The dishwasher appliance of claim 9, wherein the water funnel is shaped such that water is prevented from flowing upstream toward the inlet of the inlet duct.
 11. The dishwasher appliance of claim 1, further comprising: a vent duct having a tub channel and an ambient channel positioned within the vent duct such that the tub channel is separate from the ambient channel, wherein an inlet of the tub channel is positioned in fluid communication with the wash chamber and an inlet of the ambient channel is positioned in fluid communication with ambient air about the tub; and an insert positioned within the vent duct, the insert and the vent duct collectively defining an outlet of the tub channel and an outlet of the ambient channel, the insert positioned between the outlet of the tub channel and the outlet of the ambient channel along a transverse direction.
 12. The dishwasher appliance of claim 11, wherein the vent duct is positioned within the door, and wherein the inlet of the tub channel is positioned in fluid communication with the wash chamber when the door is closed.
 13. The dishwasher appliance of claim 11, wherein a mixed air channel is positioned within the vent duct, the mixed air channel extends from the outlets of the ambient and tub channels to an outlet of the mixed air channel, and the outlet of the mixed air channel is positioned at a bottom portion of the door, and wherein the vent duct has a diverter positioned at the outlet of the mixed air channel, wherein the diverter is operable to transition mixed air flowing through the mixed air channel substantially along a vertical direction to substantially along a direction orthogonal to the vertical direction.
 14. The dishwasher appliance of claim 11, further comprising: an ambient fan mounted to the vent duct at the ambient channel, the ambient fan operable to flow the ambient air about the tub through the ambient channel from the inlet of the ambient channel to the outlet of the ambient channel; and a controller communicatively coupled with the inlet fan and the ambient fan, the controller configured to: activate the inlet fan and the ambient fan at the same time upon commencement of a drying cycle; and activate the heating element to heat ambient air moving through the inlet duct.
 15. A dishwasher appliance, comprising: a tub defining a wash chamber; a door mounted to the tub; an inlet duct extending between an inlet in fluid communication with ambient air about the tub and an outlet in fluid communication with the wash chamber of the tub; an inlet fan positioned within or at the inlet duct, the inlet fan operable to move ambient air through the inlet duct; a heating element positioned within or at the inlet duct, the heating element operable to heat ambient air moving through the inlet duct; a vent duct having a tub channel and an ambient channel positioned within the vent duct such that the tub channel is separate from the ambient channel, an inlet of the tub channel positioned in fluid communication with the wash chamber, an inlet of the ambient channel positioned in fluid communication with ambient air about the tub; an insert positioned within the vent duct, the insert and the vent duct collectively defining an outlet of the tub channel and an outlet of the ambient channel, the insert positioned between the outlet of the tub channel and the outlet of the ambient channel; and an ambient fan mounted within or at the ambient channel of the vent duct, the ambient fan operable to flow ambient air about the tub through the ambient channel from the inlet of the ambient channel to the outlet of the ambient channel.
 16. The dishwasher appliance of claim 15, wherein the inlet duct has a water inlet positioned upstream of the heating element, and wherein the water inlet is positioned above the outlet of the inlet duct along a vertical direction.
 17. The dishwasher appliance of claim 15, wherein a mixed air channel is positioned within the vent duct, the mixed air channel extends from the outlets of the ambient and tub channels to an outlet of the mixed air channel, wherein the outlet of the mixed air channel is positioned at a bottom portion of the door, and wherein the vent duct has a diverter positioned at the outlet of the mixed air channel, wherein the diverter has one or more diverter vanes spaced along a lateral direction, the diverter is operable to transition mixed air flowing through the mixed air channel substantially along a vertical direction to substantially along a direction orthogonal to the vertical direction.
 18. The dishwasher appliance of claim 15, further comprising a first plurality of guide vanes and a second plurality of guide vanes, wherein the first plurality of guide vanes is positioned within the tub channel, the first plurality of guide vanes are spaced apart along a lateral direction, and each of the first plurality of guide vanes extends between the vent duct and the insert along a transverse direction adjacent the outlet of the tub channel, and wherein the second plurality of guide vanes is positioned within the ambient channel, the second plurality of guide vanes are spaced apart along the lateral direction, and each of the second plurality of guide vanes extends between the vent duct and the insert along the transverse direction adjacent the outlet of the ambient channel. 